1.08 Migraine Headache

Presentation

The patient comes to the ED with a steady, severe, pain in the
left or right side of the head, following ophthalmic or neurologic symptoms
which resolved as the headache developed. Scintillating castellated scotomata
in the visual field corresponding to the side of the subsequent headache are
the classic aura, but transient weakness, vertigo, or ataxia are more likely
to bring patients to the ED. Unlike other headaches, migraines are especially
likely to awaken one in the morning. There may be a family or personal history
of similar headaches as well.

What to do:

Migraine headaches (and similar recurrent headache syndromes, with or
without nausea and vomiting) are usually aborted with intravenous
prochlorperazine (Compazine) 10mg or metoclopramide (Reglan) 10mg,
with a liter of saline.

If the migraine is of recent onset, and the patient has not already taken
ergotamines, and you want to avoid starting an intravenous line, begin treat-
ment with sumatriptan (Imitrex) 6mg sc, or dihydroergotamine (DHE 45) 1mg im
(DHE can also be given iv).

If the pain has been present most of the day, and has precipitated a
secondary muscle headache, evinced by scalp tenderness, add ketorolac
(Toradol) 60mg im or ibuprofen (Motrin) 800mg po for non-steroidal anti-
inflammatory effect.

If the pain remains severe, add narcotic analgesics (meperidine, 50-l00mg
im or iv) and let the patient lie down in a dark, quiet room. It can be cruel
to attempt a complete history and physical examination (and unrealistic to
expect the patient to cooperate) before achieving some relief of pain.

After 20 minutes, when the patient is feeling a little better, undertake
the history and physical examination. If there are persistent changes in
mental status or neurological examination, a stiff neck, or fever, proceed
with computed tomography and/or lumbar puncture to rule out intracranial
hemorrhage or infection as the actual cause of the "migraine."

If the presentation is indeed consistent with a migraine, allow the patient
to sleep in the ED, undisturbed except for a brief neurological examination
each hour. Typically, the patient will awaken after a few hours, with the
headache completely resolved or much improved, and no neurological residua.

For future attacks, if there are no cardiovascular risks, prescribe a self
-injector preloaded with 6mg of sumatriptan. If the patient prefers to take
medication orally, try tablets of ergotamine 2mg and caffeine l00mg (Cafergot),
two at the first sign of the aura, then one every half hour up to a total day's
dose of 6 tablets. If nausea and vomiting prevent oral medication, Caffergot
is also available in rectal suppositories at the same dosage, but one or two
suppositories are usually sufficient to relieve a headache.

Instruct the patient to return to the ED for any change or worsening of
the usual migraine pattern, and make arrangements for medical followup. First-
time migraine attacks deserve a thorough elective neurological evaluation to
establish the diagnosis.

What not to do:

Do not prescribe medications containing egotamine, caffeine, or
barbiturates for continual prophylaxis. They will not be effective this way,
and withdrawal from these drugs may produce headaches.

Do not omit followup, especially for first attacks.

Do not miss meningitis, subarachnoid hemorrhage, glaucoma or stroke, which
may deteriorate rapidly undiagnosed.

Discussion

Even more characteristic of migraine than the aura is the
unilateral pain ("migraine" is a corruption of "hemicranium"). The
pathophysiology is probably unilateral cerebral vasospasm (producing the
neurological symptoms of the aura) followed by vasodilation (producing the
headache). Neurologic symptoms may persist into the headache phase, but the
longer they persist, the less likely they are due to the migraine. Cluster
headaches, probably also of vascular origin, are characterized by lacrimation,
rhinorrhea, and clustering in time, but the treatment of an attack is usually
the same as for migraines. Acute migraine headaches are self-limited and
respond well to placebos, so many therapies are effective. Medications for
acute migraine pass in and out of style, and the above represent popular
regimens at the time of writing. Ergotamines, phenothiazines and serotinin
inhibitors may all work by cerebral vasoconstriction. One should be cautious
in the use of ergot or serotonin agonists in any patient who has angina or
focal weakness or sensory deficits. It is possible to precipitate an ischemic
infarct of the brain or heart in such patients by using preparations which act
by causing vasoconstriction. Patients with aneurysms or A-V malformations can
present clinically as migraine patients. If there is something different about
the severity or nature of this headache, one must think of the possibility of
a subarachnoid hemorrhage. Headaches that are always on the same side
and in the same location are very suspicious for an underlying structural
lesion (e.g., aneurysm, AV malformation). Many patients seeking narcotics have
learned that faking a migraine headache is even easier than faking a ureteral
stone, but they usually do not follow through the typical course of falling
asleep after a shot of and waking up a few hours later with pain relieved. It
is a good policy to limit narcotics to one or two shots for migraine headaches,
and not prescribe oral narcotics from the ED.